At last year's UseR! conference, Johnathan Rougier presented a talk on making (and using) nomograms to estimate weights of donkeys in Africa (on joint work with Kate Milner). He fitted models to data in R (using Box-Cox transformations, something I've already mentioned here before - it's a good first thing to try for nomograms) and then used PyNomo to create the nomograms from the fitted models.